The present disclosure relates generally to air sensing devices, and in particular to portable air sensing devices for sensing concentrations of a component gas in aircraft cockpits.
Commercial aircraft typically incorporate an environmental control system (ECS) that provides a conditioned supply of air for thermal control and cabin pressurization of the aircraft. The ECS is often turned off, however, during passenger boarding when the aircraft is disconnected from airport utilities and prior to engine startup. The supply of air to the cockpit or other portions of the aircraft is therefore unconditioned and often uncirculated during passenger boarding or at other times when the ECS is inactive, thereby possibly resulting in an increased concentration of certain component gases of the cockpit air. For instance, it has been shown that cockpit carbon dioxide (CO2) levels (i.e., concentration of CO2 in the air) can rise significantly when the ECS is turned off. Such increases in CO2 can be exacerbated during times of passenger boarding, thereby resulting in significant increases in CO2 concentrations. Increased concentrations of CO2 and other gases, such as carbon monoxide (CO), have been shown to negatively impact human cognitive abilities. Accordingly, an increased concentration of such component gases arising, e.g., during passenger boarding, can potentially impact the cognitive abilities of pilots during challenging maneuvers, such as an engine fault during aircraft takeoff.